Gas-blast circuit-breaker



Jan. 25, 1966 .1. SCHNEIDE 3,231,705

GAS-BLAST G IRCUIT-BREAKER Filed Nov. 26, 1965 2 Sheets-Sheet 1 INVENTOR Josfi Schneidgr BY W JWN 291mm ATTORNEY5 GAS-BLAST CIRCUIT-BREAKER 2 Sheets-Sheet 2 Filed Nov. 26, 1963 INVENTOR Josw Schneider ATTORNEYS conduction of the pressurized Iner that the movable United States Patent 3,231,705 GAS-BLAST CIRCUIT-BREAKER J 0st Schneider, Baden, Switzerland, assignor to Akticngesellschaft Brown, Boveri & Cie, Baden, Switzerland, a joint-stock company Filed Nov. 26, 1963, Ser. No. 326,090 Claims priority, application Switzerland, Nov. 27, 1962, 13,890/ 62 Claims. (Cl. 200-148) This invention relates to electric circuit breakers of the gas blast type having one or more sets of power interrupting contacts which are separated under the influence of a pressurized gas in a switch chamber for interrupting load current, and a voltage isolating or disconnect switch connected in series with the power interrupting contacts which serves the purpose of maintaining the circuit controlled by the circuit breaker in an open state until it is desired to reclose it. The disconnect switch in accordance with the present invention is of the type which includes one or more stationary contacts and a pivotally mounted blade contact, and this blade is so mounted that when engaged with a stationary contact assembly, it will occupy a position substantially perpendicular to the axis of the switch chamber within which the power interrupting contacts are located.

-In a more conventional type of gas blast circuit breaker, the power interrupting contacts are located within tubular insulator columns upstanding upon a compressed air tank which forms a supporting base for the circuit breaker, the contact members of the disconnect switch being connected in series with the power interrupting contacts and the latter having a short pulse-like opening action in which the load current is interrupted, the contacts of the disconnect switch are thenopened to efiect the necessary voltage isolation, and the power interrupting contacts thereafter being reclosed. In such a circuit breaker, the contact members of the disconnect switch operate in the open air and the pivotally mounted blade contact'is so arranged that when engaging the correlated stationary contact member it occupies a position which is substantially perpendicular to the axis in the insulator column containing the power interrupting contacts. However, in such an arrangement, the stationary contact member of the disconnect switch is carried by a separate supporting insulator column. Although air'tank to the power interrupting contacts is satisfactory in such circuit breakers which, usually are also conveniently built into open cell switchgear, they are nevertheless difficult to incorporate into high-voltage metal-clad switchgear of the truck-mounted unit type. cipal difficulty arises because the disconnect switch blade which is substantially perpendicular to the insulator column requires complicated arrangements to permit the plug-in terminals of the unit to be located in the same It has, therefore, been previously sugvertical plane. gested to build the gas-blast circuit breaker in such manblade member 'of the disconnect switch when in its closed position lie substantially vertical 'and be located along an axis constituting a lower extension of the axis of the switch chamber housing the power interrupting contacts, the compressed air tank for supplying compresseed air to the power interrupting contacts being located to one side. However, this arrangement involves the disadvantage that the supply of compressed Y air from the storage tank to the switch chamber must include a bend of at least 90 which tends to considerably impair the action of power interrupting contacts. Moreover, the movable blade member of the disconnect switch projects laterally of the overall contour of the circuit breaker in an undesirable manner when in the open posigas from the compressed The prinof the switch chamber joined atone end to tion requiring the provision of additional space in a metalclad unit cell, particularly so far as the depth of the cell is concerned. For overcoming this latter drawback, it has been proposed to construct the disconnect switch such that its movable contact member moves axially along an axis coincident with the axis of the power interrupting contacts. For circuit breakers of the higher ratings, particularly for interrupting high order currents, this type of disconnect switch has the disadvantage that axial movement of the contact members of the disconnect switch requires driving forces of considerable magnitude in order to effect movement of the large contact masses involved with suflicient speed to attain an adequate high-speed contact breaking action. Moreover, the above-mentioned disadvantage of having a bend in the compressed gas duct is also present.

The principal object of the present invention is to provide an improved circuit breaker construction comprising series connected sets of power interrupting contacts and disconnect contacts which overcomes the disadvantages of the previously known constructions discussed above, and which at the same time may be easily adapted for use in both open cell and metal-clad switchgear. The invention is principally characterized by an improved construction for the disconnect switch component wherein the stationary and movable blade contact members thereof are supported by an insulator having a tubular portion in alignment with the vertical switch chamber housing the power interrupting contacts and through which compressed gas is delivered from a storage tank to the switch chamber, the insulator being further provided with a pair of laterally extending arm portions which lie on each side of the pivotally mounted blade contact member of the disconnect switch, and which carry at the outer ends thereof the stationary contact assembly adapted to be engaged with and disengaged from the outer end of'the blade contact. A connecting member extends from the pivoted end of the blade contact through the tubular portion of the insulator to one of the power interrupting contacts, and conductors which are embedded in the two laterally extending arm portions of the insulator are the stationary contact assembly of the disconnect switch, the other ends of these conductors reaching around the tubular portion of the insulator and being conveniently brought together. With such an improved construction, the circuit breaker rnay be easily adapted for use in metal-clad switchgear wherein plug-in members can be mounted respectively on the switch chamber of the power switch and on the tubular portion of the insulator of the disconnect switch, one plug-in member being electrically connected to one of the power inone of the power interrupting contacts and another such terminal to the stationary contact member of the disconnect switch, in which event, the conductors embedded in the arms of the insulator are not utilized.

The foregoing objects as well as other objects and advantages inherent in the invention will become more apparent from the following detailed description of diffcrent embodiments thereof and from the accompanying drawings wherein:

FIG. 1 is a view of one embodiment of a circuit breaker showing details of the improved disconnect switch coinpgnent in particular, the view being mostly in central vertical section;

FIG. 2 is a horizontal section taken on line IL-II of FIG. 1;

7 later.

FIG. 3 is a more schematic view in side elevation showing an application of the invention to metal-clad switchgear apparatus involving a closed metal cell into which the circuit breaker is pushed; and

FIG. 4 is also a schematic view in side elevation illustrating another application of the invention to switchgear apparatus involving open cell installation.

With reference now to the drawings and to FIGS. 1 and 2 in particular, the insulator which supports the contact elements of the disconnect switch is indicated generally at 1 and can be made from a casting resin. It includes a tubular portion 1a upwardly through which a pressurized gas such as compressed air is delivered from a storage tank to the power interrupting contact members, not illustrated, but which are enclosed by the switch chamber 6. Also included are two laterally extending arm portions 1b in each of which a conductor 2 is cast in. Conductors 2 protrude through the outer ends of the arms 1b and, by means of a connecting member 9 extending between such ends, support the stationary contact assembly of the disconnect switch. This stationary contact assembly is constituted by a pair of spring clip type contacts 8 between which is received the outer, free end of the pivotally mounted blade contact 7 of the disconnect switch.

The other end portions of the conductors 2 are embedded in the tubular portion 1a of the insulator and conveniently meet at a common junction point Zn from which. an electrical connection is taken out to one of the external terminal members 4- of the circuit breaker. Terminal member 4 can be of the shrouded socket type. This particular construction is especially adapted for use with metal-clad switchgear of the plug-in type shown in FIG. 3, and which will be described in further detail The conductors 2 can thus be constituted as a single U-shaped conductor member.

The inner end of contact blade 7 by pivot pin on part 312 of a metallic, tubular electrically conductive fitting 3 cast in which the insulator and which extends laterally through the tubular insulator part 1a to a point located intermediate the insulator arms 1b. The fitting 3 also includes a tubular portion 3a extending upwardly, the upper end of which is secured electrically to one of the two load interrupting contacts of the power switch, preferably a stationary contact. The other load interrupting contact which would thus be a movable contact member is electrically connected is pivotally mounted to the other external terminal member 5 which can be of the same construction as terminal 4.

In order to make the junction of the insulator arms 1b with the tubular portion In more rigid, the insulator structure further preferably includes upper and lower webs 1c located in a vertical plane.

It will be noted that FIG. 1 shows the blade contact 7 of the disconnect switch at an upwardly inclined position when separated from the stationary contact assembly 8. FIG. 2 shows the blade contact 7 in the position engaging the stationary contact assembly 8 and is at such time horizontal, i.e. it is perpendicular to the ver 'tic-al axis of the tubular insulator 1 and the superposed chamber 6 of the load interrupting contacts, the latter not being shown in either FIG. 1 or 2 but which can be of conventional construction involving relatively movable contact members which when separated are subjected to blasting by the pressurized gas from the storage tank in order to expedite extinction of'the arc. The means for actuating the switch contact blade 7 is also not shown in FIG. 1 .or 2, but can be conventional pneumatic motor means as shown in FIG. 3.

When the circuit breaker shown in FIGS. 1 and 2 is closed, the current path through the series connected load breaking contacts of the power switch and the voltage isolating contacts of the disconnect switch can be traced,

through the breaker, beginning at terminal 4 and continuing through the parts 2, 9, 8, '7, 3, 3a, and the load breaking contacts within chamber 6 to the other terminal 5.

Operation of the circuit breaker is in accordance with the usual sequential practice of first disengaging the power interrupting contacts to break the load current by a means of a brief pressurized gas pulse applied to the contacts, then opening the disconnect contacts 7, 8 to establish a voltage isolating gap, and then permitting the power interrupting contacts to reclose, these contacts being of the customary construction wherein they are normally spring loaded to a closed position and become disengaged only when a pressurized gas pulse is applied to the contact mechanism. The circuit breaker is now in a stabilized, voltage isolated position, and can be reclosed at any time simply by reclosing the contacts 7, 8 of the disconnect switch, the contact blade 7 being swung downwardly by its drive means in the direction of the arrow from the position of FIG. 1 to the position of FIG. 2.

FIG. 3 illustrates an embodiment of the invention wherein a circuit breaker essentially of the same constructlon as shown in FIGS. 1 and 2 is adapted for use with metal-clad, i.e. metal enclosed switchgear cells. The circuit breaker unit is made mobile by using a wheeled underframe 11 on which is mounted a compressed air tank 12. The latter mounts a blast valve casing structure 13 which in turn supports the insulator and disconnect switch structure which is essentially the same as illustrated in FIGS. 1 and 2. Mounted atop insulator 1 is the switch chamber 6 and the load interrupting contact assembly within the same, and mounted atop switch chamber 6 is a cooling unit 14 for cooling the are extinction gases which are exhausted from chamber 6. All of these elements are in axial alignment so that flow of pressurized gas from tank 12 is vertically upward.

In FIG. 3 are also depicted some of the other details such as the actuator rod 15 of insulating material which extends to the contact blade 7 from a pneumatically operated drive device 16 and serves to open and close the blade 7 with respect to the stationary contact assembly 3. Blast valve 13 opened to effect separation of the load breaking contacts and the drive unit 16 for the contact blade of the disconnect switch are controlled by a unit indicated generally at 21 and which is also mounted on the truck 11. In FIG. 3, the mobile circuit breaker is illustrated as having already been pushed into its metallic cell 22, and the contact terminals 4, 5 which can be in the form of sockets, engaged with the stationary lower and upper pin-shaped countercontacts 17, 18 inside of the metal cell 22. The insulator 1 thus simultaneously provides insulation between the metallic live compo nents of the disconnect switch and the column supporting and fixing means which are at ground potential. In the embodiment of FIG. 3, such grounded supporting and fixing means are the blast valve 13. This arrangement permits the overall height of the circuit breaker to be substantially reduced below that of more conventionally constructed circuit breakers of this general type because the usual auxiliary insulating supporting columns are eliminated.

In some instances, it becomes necessary to locate the lower terminal member 4 at a level somewhat below the pivot axis of the blade contact 7 in order to align the terminal with the lower contact pin 17 of the cell 22, which in some cases is fixed by other factors and cannot be. relocated. This can be easily accomplished as indicated in FIG. 3 by casting in to the insulator 1 an level, the terminal member or shield 20 to establish a better insulating barrier between terminal 4 and the blast valve casing 13.

FIG. 4 illustrates an embodiment of the invention which comprises essentially the same structural components as are shown in FIG. 3. However, it will be noted that the insulator 1 is rotated through 180 about the axis of the insulator from the position shown in FIG. 3 so that the stationary contact assembly 8 of the disconnect switch faces in the opposite direction. A lower strap type terminal member 4a utilized in lieu of socket terminal 4 is secured to the stationary contact assembly 8 and an upper strap type terminal member a utilized in lieu of socket terminal 5 is secured to one of the load breaking contacts. A flat section bar 23 having a 90 bend extending upwardly is then secured to the lower terminal 4a, and a similar bar 24 is secured to the upper terminal 5a. This form of construction is particularly suitable "for building into open type switchgear cells, in which case the control unit 21 can be conveniently located on the side of the blast valve 13 opposite the drive unit 16 and disconnect switch. In the embodiment of FIG. 4, it will be evident that the conductors 2 are not utilized since terminal 4a is located at the opposite ends of these conductors, i.e. directly at the stationary contact assembly 8.

In conclusion, it is to be understood that while the illustrated embodiments of the inventive concept are preferred, various modifications in the construction and arrangement of components can be adapted without, however, departing from the spirit and scope of the inventive concept as defined in the appended claims.

I claim:

1. In a gas blast circuit breaker the combination comprising a power switch chamber within which are located a set of load interrupting contacts, an insulator member having a tubular portion located below said power switch chamber and through which a pressurized gas is passed into said chamber, said insulator member also including a pair of spaced laterally extending arms, a disconnect switch connected in series with said power switch, said disconnect switch including stationary contact means supported at the outer ends of said insulator arms and a pivotally mounted contact blade disposed between said insulator arms, said contact blade when engaged with said stationary contact means being disposed perpendicular to the axis of said power switch chamber, connector means extending from the pivoted end of said contact blade to one of said load interrupting contacts, and conductor means embedded in said insulator member, said conductor means extending around the tubular portion of said insulator member and through said insulator arms so as to project beyond the ends thereof, and means connecting the projecting ends of said conductor means with said stationary contact means of said disconnect switch.

2. A gas blast circuit breaker as defined in claim 1 wherein said connector means includes a metallic fitting embedded in the tubular portion of said insulator, said metallic fitting including a tubular projection extending upwardly to one of said load interrupting contacts and a lateral projection extending through the wall of the tubular portion of said insulator to a position intermediate said insulator arms, and a pivot connection for said contact blade on said lateral projection.

3. A gas blast circuit breaker as defined in claim 1 and which further includes an external terminal member connected to that part of said conductor means which extends around the tubular portion of said insulator.

4. A gas blast circuit breaker as defined in claim 3 and wherein said stationary contact means is constituted by spring clip means supported by a transverse member connected between the outer ends of said conductor means.

5. A gas blast circuit breaker as defined in claim 1 and which further includes an external terminal member connected to said stationary contact means of said disconnect switch.

6. A gas blast circuit breaker as defined in claim 1 wherein said insulator member is mounted rotatably below said switch chamber about the axis thereof such that the laterally extending arms can be selectively oriented to face in a first direction or in a second direction located from said first direction.

7. A gas blast circuit breaker as defined in claim 1 and which further includes a first external terminal member connected to those parts of said conductors which extend around the tubular portion of said insulator and a second external terminal member connected to the other of said load breaking contacts, said external terminal members extending in the same direction and in the same vertical plane.

8. A gas blast circuit breaker as defined in claim 1 and which further includes a first external terminal member connected to said stationary contact means of said disconnect switch and a second external terminal member connected to the other of said load breaking contacts, said external terminal members extending in the same direction and in the same vertical plane.

9. A gas blast circuit breaker as defined in claim 1 and wherein said insulator arms include vertically disposed reinforcing webs.

10. A gas blast circuit breaker as define-d in claim 1 wherein said conductor means is constituted by a U-shaped conductor the bight portion of which extends around the tubular portion of said insulator and the legs of which extend beyond the outer ends of said insulator arms.

No references cited.

KATHLEEN H. CLAFFY, Primary Examiner. 

1. IN A GAS BLAST CIRCUIT BREAKER THE COMBINATION COMPRISING A POWER SWITCH CHAMBER WITHIN WHICH ARE LOCATED A SET OF LOAD INTERRUPTING CONTACTS, AN INSULATOR MEMBER HAVING A TUBULAR PORTION LOCATED BELOW SAID POWER SWITCH CHAMBER AND THROUGH WHICH A PRESSURIZED GAS IS PASSED INTO SAID CHAMBER, SAID INSULATOR MEMBER ALSO INCLUDING A PAIR OF SPACED LATERALLY EXTENDING ARMS, A DISCONNECT SWITCH CONNECTED IN SERIES WITH SAID POWER, SWITCH, SAID DISCONNECT SWITCH INCLUDING STATIONARY CONTACT MEANS SUPPORTED AT THE OUTER ENDS OF SAID INSULATOR ARMS AND A PIVOTALLY MOUNTED CONTACT BLADE DISPOSED BETWEEN SAID INSULATOR ARMS, SAID CONTACT BLADE WHEN ENGAGED WITH SAID STATIONAY CONTACT MEANS BEING DISPOSED PERPENDICULAR TO THE AXIS OF SAID POWER SWITCH CHAMBER, CONNECTOR MEANS EXTENDING FROM THE PIVOTED END OF SAID CONTACT BLADE TO ONE OF SAID LOAD INTERRUPTING CONTACTS, AND CONDUCTOR MEANS EMBEDDED IN SAID INSULATOR MEMBER, SAID CONDUCTOR MEANS EXTENDING AROUND THE TUBULAR PORTION OF SAID INSULATOR MEMBER AND THROUGH SAID INSULATOR ARMS SO AS TO PROJECT BEYOND THE ENDS THEREOF, AND MEANS CONNECTING THE PROJECTING ENDS OF SAID CONDUCTOR MEANS WITH SAID STATIONARY CONTACT MEANS OF SAID DISCONNECT SWITCH. 